I have a 2003 Durango with a 4.7L engine. When I get to 55 or 60 and start going up a hill or get to a situation where it down shifts the engine starts to stutter and acts like it's missing on a cylinder. It runs great other than that. I removed one of the spark plugs to take a look and it was looking pretty worn. Could this be the only cause of this? Also it looks like what I'm assuming is the throttle body directly above one of the plugs. How do I get around this to change it? I'm a pretty amature mechanic and could use some advice. What do you think the problem is and how do I get at this last spark plug? THANKS!!

 

all the spark plugs can be accessed by unbolting the coil for each plug (one coil = one plug) and then putting a spark plug wrench on an extenstion into the hole, you do need to take off the air box (plastic box attached to throttle body) in order to get them all out, it should only be on with two bolts.

remember to use copper core champion plugs ONLY and gap to .040

 

the last plug is just like the others, you do not need to remove the TB but you will need to get some leverage.. maybe stand on the bumper and remove just like the others. NKG or Champions work well

 

Replace the spark plugs with Champion Copper (cheapo $2 plugs) and gap at .040 and clean the TB.